A superlative means that something is the top, the number one, the best, and there is only one, so we use a "the". There may be minor exceptions, but I think using a "the" will get it right most of the time.

A superlative means that something is the top, the number one, the best, and there is only one, so we use a "the". There may be minor exceptions, but I think using a "the" will get it right most of the time.